Automatic pressure-controller.



-I UNITED sTATEs.

TATENT OFFICE. l

HOWARD REGINALD DUNBAR; or-oANToN, MASSACHUSETTS, ASSIGNoR To LAMSoN CONSOLIDATED STORE SERVICE COMPANY, F NEWARK, NEW JERSEY,A A COR- PORATION 0F NEW JERSEY.

AUTOMATIC PRESsURE-coNTRer.LER-

- in connection with pneumatic despatch tubesystems wherein a reserve air pressurenor.; vacuum is maintainedand wheresaidfr'ff) 'serve' is. irregularly v.drawn uponfor the transmission of carriers causing"varyingv fluctuations i-n the pressure.4v

The object of my invention is to provide mechanism for controlling the 'pressure-` maintaining member to'fmaintain a.l predetermined pressure and-tio provide meansjfor preventingthe fluctationsffrom actingsuddenly upon said controlling mechanism.

In the accompanying drawings which illustrate a construction embodying my 'inf vention, the ligure represents an, elevation partly in sectionof 'the' device in operating` connection with a vacuum drum.

The device as shown is adaptedto operate to maintain a constant' or redetermlned vacuum in the drum A to whic is connected the main Supply pipe A a feeder for numerous pneumatic despatch tubes.

ably by a blower or pump drivenby a va-A riable speed motor andcontrolled by a rheostat B.

C is an automatic controller-for the rhe'ostat B. The rheostat B has the twn contact arms B B2 pivoted on the post B5, the arxn B adapted to cooperate with a series of contacts B3 controlling the resistance` in the field of the motor and the arm B2 adapted to cooperate with a series of contacts B'l which control the resistance in the armature B is a handle attached to the arm B to move the saine to start the motor into operation. f i

BT represents the usual magnet` for holding the arm B2 at its highest -point Where the resistance' in the armature circuit is at minimum. v The pressure controller .or cylinder() car ries mounted therein vthe pistou ,C secured Specification@ Iiettrs Patent. Appunon nie'afly 1;' ibo?. serial N9. 381,653.

The air' may be exhausted fromlthe drum A prefer-- [Patented Nov. 29., 191e.

tothe piston rod C2 by a pin C3, the 'upper end of thefsa'idrrod beine pivoted at- Ci' to valever C. One end of the lever C is pivote'd to a link C7 at C", the opposite end of said link beingpivoted` at C" to anextenson C1", onfthe cylinder'. C. A weight W is 'lVz, inthelever C" and Seeuredthereto by Y a bolt W The upper part-of the c ylinder fthe port and' pipe A2- with the .vacuum 1n:

the mainsupply pipevA. j A32 y 'cylinderfordajsh" pot D .secured to the lower partjof thel cylinder Gand has mounted 'thereinl-thei-ppiston D' secured .to an exteusionjof thepistonrod C2 by a pin D.V

dash potl) ,asthe' piston VD. moves up or down. 'g' v 1 l D isla-portvconnecting. the lower part of the cylinder-C belowthe iston C Awith the 4filling of the dash pot D with oil.V 1 I 1 f Mounted on the arm B is a plate b carryine-a stud bon' which is mountedthe fiber upper edge of the lever C by the tension of' the spring Bs, andthrough which the leyer C".o crates tomove the arm B up or down onk t e contacts for resistance B3. "When the system is to'be started up to create the drum A, the operator starts the motor talus the arm B2', and the resistance in both the armature and field circuit-5- of the inotor is reduced to' aminimumlhe motor now started, thc .air .gradually exhausts 'from the drum A, and th%vacuuu1acting through the 'port A* exhausts' the air above the piston C causing the piston toiise until the lever .(l hasulifted sutlieientlly to engage the' rollJ/"at a' predetermined height. The amount of'vacuum is predcteruiined by thc adjustment ofthe weight W on' the lever C".

During the use of thesysteiu, lthe pressure C-above the pistonC communicates t rou h.

ajvalvev ada ted to shutl olf 'the' f..vacuuinjjfrom the cy inder C.: A smallerl rollb which is held normally against the a normal working vacuum or-pressure inadapted'to beadjusted to any of the holes v Tlie'oriliees or holesgDz are to permit-.the restricted fo'w of the oilfc'ontained in the l atmosphere, and D isap ug permitting thev and .pump connected with said drum A as hiehest` )osition' where the luaenet B7 rep zo in the drum A and pipe ii-luot11ates and therefore the piston C is raised or lowered moving the arm B and varying the resist# ance in the field of the motor, such varieA tions operating to speed up the motor when the pressure varies in one direction and to slow down the motor when the pressure varies in the opposite direction. Thus it will be seen theta constant pressure will be' ing through the orifices D3 in the piston D which steadies und graduates the velocity of the movement of the piston C. When the .system is shutdown/fthe erin-'B2 is released and the motor stopped by throwing out the usuai cui. out or switch whereupon the'parts assume the non-operating position shown in the figure. e

Having thus described the nature of my invention and. set forth a construction ernbodying the same, what I claim as neur and desireto secure by Leters Patent Vof the United States is:

1. In an automatic pressure controller a source of air-pressure, e supply pipe -o a pneumatic despatch tube system communieating with said source oi? air-pressure, a cylinder communicating at one end with seid supply pipe and opening at the other end to the outside air, aV piston niovablezin www said cylinder by the variation of pressure in the cylinder through the letters communication with Said sup 1y pipe, A:i pivoied lever actuated by sai iston, und the hinged contact-arm of a r eostat having slidm engagement with said lever and coutrolle by the movement of said lever.

2. In en automatic, pressure controller 'u source of air pressure, e supply pipe o a pneumatic despatch tube stem communicati with said Source o air-pressure, la. cyliiier communicating at one-end with said sup ly pipe and opening' et the other end to t e outside `air, a. pistonmovable in said cylinder by the vanation of pressure in the cylinder through the latters com#v municaticn with said supply pipe, a pistorlrod leading from said piston to the exterior of the cylinder, a lever having a, movable' fulerurn connected, with the outer end of -saidfpiston-rod-,va Weight ad'ustable on the free end of saidleverfnndit ehin ed con-v tact-arm of ulrheostut havin 'a sli ingengagement withv said lever-an controlled .by the movement of said lever.

-In testimony"`wirereo I havesgned my name to this specieaition lin thev presence o two subscribing witnesses, this 215th'v dayof June A D. A .y

.EDWARD REGINALD Witnesses: i

CLARENCE H. Gimmy, WARREN B. ROBINSON. 

